This two-year qualitative participatory research project examines practical guidelines for supervision. Sixteen experienced supervisors across professional settings of family therapy, child protection, and specialty mental health services in the geographical regions of Northern Norway and Northern Sweden outline four main practical guidelines in supervision based on their supervisory practices: (1) elaborating an agreed-upon contract; (2) exploring potential formats; (3) exploring contents; (4) acknowledging responsibility for process and dilemmas. Participants summarised how they generated mutual growth in supervisory relationships, while being respectful of the first-person perspective of supervisees. The study challenges pre-dominating guidelines about deficit-or developmental stage-oriented supervision. It illustrates reflecting processes and a polyphonic orientation in supervision by welcoming diversity, wondering, and tolerance for the not-yet-decided among involved persons in a mutual exploration and calibration of relevant knowledge. It outlines a dialogical research for sharing, exploring, and questioning knowledge as beneficial for whom, told by whom, and evaluated by whom.1 Supervision is mandatory in family therapy educational programs, clinical specialisation, and included as ordinary working methods in family therapy, child protection, and mental health services. However, practical guidelines for doing both supervision and practice-anchored research on supervision are often asked for. 2 Therefore, a two-year participatory qualitative research project was undertaken inviting experienced, practicing supervisors from family therapy, child protection and specialty mental health services, across professions and theoretical orientations, to outline their main practical guidelines for supervision. 3 Participants (16) joined a two-year 'dialogical and practical research forum, ' where their own and others' live, ongoing supervision was performed, discussed, and reflected upon to allow practical guidelines to be articulated and summarised. 4 Four main guidelines emerged: (1) to elaborate an agreed-upon contract;(2) to explore potential formats(3) to explore contents, and (4) to acknowledge the supervisor's responsibility for process and dilemmas. 5 The study illustrates reflecting processes and a polyphonic orientation in supervision by welcoming diversity, wondering, and tolerance for the not-yet-decided among involved persons in a mutual exploration and calibration of relevant knowledge. It outlines a dialogical research for sharing, exploring, and questioning knowledge as beneficial for whom, told by whom, and evaluated by whom.